The present invention relates to mobile carriers. Particularly, the invention relates to trailers.
Mobile carriers have been used since nearly the beginning of humans. With the advent of the wheel and the advent of vehicles, such as automobiles, trailers became a common platform to carry items. Typically, a trailer includes a frame made of strong metal, such as steel or aluminum, an axle containing one or more wheels attached to the frame, and an optional body attached to the frame to cover the trailer storage area. The trailer body is generally made of aluminum due to its relatively low cost and especially its light weight. Structural members are generally attached to the inside of the body. Generally, to provide needed stiffness and structural integrity, structural members are either welded, riveted, or bolted to the inside of the body. This construction allows the exterior to be smooth to lessen wind drag, but also lessens valuable storage space.
As a separate issue, there are at least two design difficulties that have plagued designers. The first is weight. Although the production of vehicles with more powerful engines allows the use of larger trailers, the weight of the trailers is cumbersome. In many cases, the trailer is too large to lift by hand to connect to the vehicle. Typically, the front part of the trailer that the vehicle connects to is called the xe2x80x9ctonguexe2x80x9d and contains a trailer hitch. On larger trailers, the tongue and hitch are raised through mechanical, hydraulic, or pneumatic mechanisms, the vehicle backs up to the trailer hitch, the trailer hitch is lowered onto a connecting portion on the vehicle, and the connection is made for pulling or other use. Even smaller trailers can sometimes be quite cumbersome from the front weight called xe2x80x9ctongue weightxe2x80x9d or from just the mass of the body and frame. Thus, some individuals are not able to easily maneuver even smaller sized trailers because of its inherent structural weight.
The second problem is stability of the trailer. The stability of the trailer can determine the safety of the trailer and, thus, the trip in which the trailer is used. A trailer can sway from side to side due to a poor design, uneven loading, or other factors. It is known that an unstable trailer has caused vehicle accidents. In some cases, an unstable and swerving trailer has been known to even overturn the pulling vehicle. Stability is particularly sensitive on smaller trailers. Further, enclosed vehicles typically have a higher center of gravity due to the higher enclosing structure and can have increased tendency to become unstable.
The size of smaller trailers can particularly cause difficulty in stability. Thus, in trying to meet both of the above design challenges of weight and stability, a small, lightweight trailer can meet the first challenge, but fail the second challenge.
Therefore, there remains a need for a lightweight trailer that can retain a reasonable amount of stability even for small sizes. Further, there remains a need for a lightweight, stable trailer that can increase the amount of storage space used for structural members in the storage area of the trailer, but still offer aerodynamic designs to reduce wind drag. The present invention answers these needs.
The present invention provides a molded trailer shell that can be coupled to a frame, a trailer hitch, and one or more wheels to form a trailer. The trailer shell is advantageously formed by rotational molding. In at least one embodiment, the trailer shell includes a front, two sides, a top, and various external ribs molded with the shell. Further, the ribs can be shaped to aerodynamically channel the air to produce a stable towing trailer.
In general, the invention provides an aerodynamic trailer, which includes a trailer frame comprising a forward portion, a rearward portion, and a trailer hitch disposed on the forward portion. A molded shell is coupled to the frame, the shell comprising a top fin disposed longitudinally along a top of the shell and extending outwardly from a top face of the shell.
The invention also provides an aerodynamic trailer comprising a frame, a trailer hitch coupled to the frame, a wheel coupled to the frame, and a molded shell coupled to the frame. The shell comprises a top defining a top face and having a top fin extending longitudinally along the top, a side defining a side face and having a side fin extending vertically along said side, a wind scoop having a tapered surface disposed on the top and in proximity to a rearward portion of the trailer, and a front defining a front face and coupled to the top and side. The invention also provides a trailer shell, comprising a top, a side, and a front of the trailer shell integrally formed by a process of rotational molding.
In a further embodiment, a method of forming a molded trailer shell is provided, comprising placing a moldable material in a rotational molding machine having a mold, the material being sufficient to form a molded trailer shell, spinning a portion of the rotational molding machine in multiple axis to form the trailer shell, and extracting the trailer shell from the rotational molding machine.